Super Seven S2 Clutch Issues

[TEM]

All I did was push the slave cylinder back until the circlip was firm against the mount then adjusted the domed nut to give the appropriate 1/16" gap.  If you don't push the slave back then for sure you will have a gap that will limit the stroke.

[SENC]

A quick search in my files didn't yield anything about the washer but the Seven owners manual does indicate there should be 2 circlips.

 

 

On a previous note while checking the Lotus Seven Parts manual, I notice it refers to the clutch master being 5/8" - contradicting the 3/4 listed in the Girling catalog and other places.

 

[SENC]

I'll have to measure the mount on the bellhousings of my Seven and Elan - thinking it is also possible the mounts on earlier bellhousings were shorter in length.

[SENC]

9 minutes ago, TEM said:

All I did was push the slave cylinder back until the circlip was firm against the mount then adjusted the domed nut to give the appropriate 1/16" gap.  If you don't push the slave back then for sure you will have a gap that will limit the stroke.

Agree that ensuring it was fully seated should yield the same end result if you have enough adjustment room on the rod.

 

Regarding setting the rod/dome nut versus the clutch lever - as I recall that process includes manually holding the lever rearward (away from the slave) and setting the gap (without the spring in place).  Is that what you did?

[TEM]

Yes, I set the gap without the spring while wiggling the arm to make sure I had the gap correct.  It's a domed nut so the 1/16" is a bit of an approximation.  I know I didn't have too much play there because when I added .2" of preload on the arm, the clutch slipped badly to the point of being undriveable.

[TEM]

I never really understood the two circlips note in the manual.  My one circlip fills the groove.  I don't know where the second one is supposed to go.  Maybe one was used like your washer.

[MV8]

14 hours ago, TEM said:

That is the correct formula for a 5/8" master and 3/4" slave.  Your results match my previous post.

 

As I mentioned, I remove the slave cylinder from the bell housing and raise it above the master cylinder.  I clamp the slave cylinder so that the piston doesn't eject itself and then bleed as normal.  This keeps the air pocket at the highest point.  I first bench bleed the master.

I've found multiple methods are sometimes needed to fully bleed a system and can easily account for your issues. I typically use the tools in this video but on the bleed screw and usually bleed a clutch the opposite of brakes as they do in this video.

 

 

[MV8]

A kit like this would be fine for just about anything. Enough fluid is added to the jar to cover the end of the hose inside and the lid is kept tight so the vacuum level is maintained. Again, don't bleed a clutch the way you bleed brakes.

 

https://www.ebay.com/itm/176413002663?itmmeta=01HZS2DQ5KE4250HFW4ZWYT3KV&hash=item291308cba7:g:k3QAAOSwZfFmYqDS&itmprp=enc%3AAQAJAAAA4DblZ6GIUIg8erC3knJnm%2BVQz%2BvA%2FtxwT414IR%2F0aaxokuv7LUC8qgeDpt0l90uP9%2FxTdSTj1zhwbfCjQYe6sclkyEd7IpQJvL4OLKZpR4GZ4TCySFrcR6Po7etfpr%2Bh%2B0U35LRY%2BGxhkRF4hu0sCw3qnygnGEWZZiA8N%2B9me%2FE4Tgzofpmtyfo%2Ffxy3jzvwWJEgudVkFX3iebv2ECAJJcF%2BY5P9invnMLGe0Hb2%2FqnMkvG4f6SDkCV6fou0iRoysysK4gT2KXYHTv8deVeqxuE3Ihp5auUhXVq6QR57gQh8|tkp%3ABk9SR_7ytqL-Yw

[TEM]

The Dry vacuume bleed is interesting.  I will see if it makes a difference. 

[fotsyr]

Your pressure plate is most probably frozen to the flywheel. 2 options. Start the car and make sure it gets up to operating temp. Turn off engine, put in gear and start on key and drive off, it will loosen off eventually. Or do the same jack up rear end, with car in gear and running. Drop onto the ground and the shock will free off the disc plate.

M/C 5/8", slave 3/4.

[fotsyr]

Your clutch disc is most probably frozen to the flywheel. 2 options. Start the car and make sure it gets up to operating temp. Turn off engine, put in gear and start on key and drive off, it will loosen off eventually. Or do the same jack up rear end, with car in gear and running. Drop onto the ground and the shock will free off the disc plate.

M/C 5/8", slave 3/4.

Edited June 11 by fotsyr
wrong repsonse

[TEM]

Clutch is not frozen to the flywheel.  The clutch acts normal some of the time and can't get in gear others.  I can rev the engine with the clutch pressed and the car in gear and it does not creep.

[TEM]

Slave has been rebuilt and I tried every bleed procedure suggested.  No improvement.

I replaced the hose with a hard line.  This required me to bleed the slave while attached to the bell housing.  This is where I tried all of the suggestions.  Except the dry vacuum method which I could not do due to the design of these master cylinder.  The port is in a small cavity 90deg form vertical.  I do not have an angled fitting to try this.  All of the methods did remove air from the system but always left a little remaining.  I judged this by a small amount of "squish" once the linkage play has been taken up.  I can feel and see this squish while pressing the MC rod by hand.  Bleeding the slave above the MC seems to do a better job of getting all of the air out.

 

I also swapped the brake and clutch MC's putting the 3/4" MC on the clutch.  As expected, the pedal throw was much shorted (and harder) but there was no improvement in getting into gear.  I don't need to drive the car to experience this.  While idling, I can sometimes get into gear with no problem and sometimes I can't get any gears.  I can always find a way to get it into 1st gear (which is my baseline for testing).  Sometimes just selecting another gear first will allow me to get into 1st gear.  If that doesn't work then sometimes slowly lifting off the clutch pedal while pushing the gear knob into 1st will allow it to drop in.  Sometimes I really have to fish around and try different combinations to find something that works.  Usually I can get into 1st with relative ease when I first start a drive.  It seems to be harder to shift and harder to get into 1st after about two miles of 20-30mph driving.  I have not tried anything further as I fear being stuck at a stop sign or light with people behind me.

[SENC]

And this is only happening when the engine is running?  Easy gear movements when not running, colf or hot?

 

I suspect you're getting closer to few options but to pull the engine and gearbox for a look.

 

Have you changed the gearbox oil?  How'd the old oil look?  If you haven't, I'd drain it and put in some Redline MTL - that definitely made a notable difference for mine.

Edited June 11 by SENC

[MV8]

What is the distance between the bell housing slave mounting boss and the release fork outboard and parallel to the pushrod? Senc can compare his or you can check the clearance with some one fully pressing the clutch pedal. I suspect this may be one of those applications that required a spacer on the release bearing. If so, and the spacer is missing, the fork may contact the rear edge of the bell housing window just as the clutch is almost fully released. This would explain the hard stop you were referring to before.

[SENC]

There isn't a spacer for the release bearing beyond the carrier - but your line of thinking does bring a couple possibilities to mind...

 

As this car was used for racing, could it have been fitted with a larger 8.25" clutch?  These were standard, I think, on Elan plus 2s so should have been a fairly straightforward way to get a larger clutch in place.  The biggest difference (other than diameter) is that these didn't have a thrust plate on the fingers and required a different, rounded/domed release bearing.  Perhaps the wrong release bearing was used?  You may be able to identify the clutch bearing type and whether a thrust plate is on thw clutch fingers via boroscope.

 

Additionally, there was a different sized bearing carrier that was used in some plus 2s (5-speed, I think), so perhaps something got mixed up in a prior rebuild?

 

Another possibility is that the fork itself is getting weak and flexing.

Edited June 11 by SENC

[MV8]

I don't know which transmission he has in this one. The 2821E bell (twin cam application) requires the bearing spacer when used with a crossflow and I assume pre-crossflow). This combo is supposed to be common on the S4. There were a few other original mismatch combos.

[jbcollier]

He dialled in a few mm of preload and the clutch released fully but then started slipping.  One of two things:

 

- clutch disc/pressure plate is warped and requires more than normal travel to release;

 

- one/both of his "rebuilt" clutch slave and master is worn internally and is not giving full travel.

[SENC]

Was looking through an old DBE catalogue for something and took a peek at the clutch section while there.  Adding pictures of a couple pages.

 

Of note, indication that pushrod engines used a 3/4" MC (matching the Girling information but contradicting the Lotus parts manual) and a description of the different bearing carriers/hubs - and the spacer MV8 refers to.  There is a specific note indicating there are actually several different sizes.  I don't remember seeing this anywhere else, and have to admit I don't recall which carrier I used rebuilding mine - time to go look through rebuild pictures for a clue!

 

 

Edited June 11 by SENC

[SENC]

And an application chart from the same catalogue indicating the various combinations...